/* 设置全局字体和背景颜色 */
body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f8f9fa;
    color: #343a40;
    line-height: 1.6;
}

/* 设置容器样式 */
.container {
    max-width: 960px;
    margin: 0 auto;
    padding: 20px;
    background-color: #ffffff;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    margin-top: 50px;
}

/* 设置标题样式 */
h2 {
    color: #212529;
    font-size: 2.2rem;
    margin-bottom: 30px;
    text-align: center;
    font-weight: 600;
}

h4 {
    color: #495057;
    font-size: 1.5rem;
    font-weight: 500;
}

/* 设置按钮样式 */
.btn {
    background-color: #007bff;
    color: #ffffff;
    border: none;
    padding: 10px 20px;
    border-radius: 5px;
    cursor: pointer;
    text-decoration: none;
    transition: background-color 0.3s ease;
}

.btn:hover {
    background-color: #0056b3;
}

/* 设置卡片样式 */
.card {
    border: none;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.07);
}

.card-body {
    padding: 30px;
}

/* 设置柱状图容器样式 */
#plotly-chart {
    margin-top: 20px;
}

/* 设置 flex 布局样式 */
.d-flex {
    display: flex;
}

.justify-content-between {
    justify-content: space-between;
}

.align-items-center {
    align-items: center;
}

.mb-4 {
    margin-bottom: 1.5rem;
}